Adjustable surveying-target.



J. G. McMiLLAN,

ADJUSTABLE SURVEYING TARGET.

APPLICATION FILED OCT. I. mu.

1 ,272,069. Patented July 9, 1918.

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ADJUSTABLE SURVEYING-TARGET.

Specification of Letters Patent.

Patented July 9, 1918.

Application filed October 1, 1917. Serial No. 194,190.

To all whom it may concern:

Be it known that I, J GEN GILMORE Mc- MILLAN, a citizen of the United States, residing at San Jose, in the county of Santa Clara and State of California, have invented a new and useful Improvement in Adjustable Surveying-Targets, of which the following is a specification.

This invention relates to adjustable surveying targets, and its objects are.

First; to provide an adjustable target for spirit leveling surveying, and tachymetry stadia surveying that may be sighted from either back or front of the target.

Second; to provide an adjustable surveying target that can be used on any ordinary ranging round rod of suitable diameter, accurately graduated into feet or any standard unit of length.

A still further object of my invention is to provide an adjustable surveying target that may be adjusted to a rod in any required position, and one that Will show its distance from either end of the rod in units and subdivisions thereof of a standard unit of length.

lVith these and other objects in view my invention will be more fully described and illustrated in the accompanying drawings, and then more specifically pointed out in the claim, which is attached to and forms a part of this application.

In the drawings:

Figure 1 is a front view of my adjustable surveying target attached to a unit graduated pole or rod.

Fig. 2 is a detail elevation of my adjustable surveying metal target, showing slot in the body portion with subdivisions of the unit on each side of the slot, and metal clamp in place.

Fig. 3 is a detail plan view of Fig. 2, showing clamp and thumb screw in position.

Corresponding and like parts are referred to in the following description and indicated in all the views of the drawings by the same reference characters.

My invention consists of a metal target 1, having a hollow body portion 2 integral therewith. The body portion corresponds in length to a unit division on the rod. A longitudinal slot 3 is shown in the face of the body portion 2, of sufficient width to observe the unit division on the rod. On each side of slot 3 are the subdivisions 4; of the unit, one side reading from the bottom upward, the other side reading from the top downward. The target 1 may be painted red and white, or black and white. Any suitable metallic clamp 5 and thumb screw 6 may be used, the clamp 5 being made an integral part of body portion 2 by brazing or soldering thereto and is adapted to hold target 1 and body portion 2 in place on any ordinary round pole or rod.

Various changes in the form, proportions and minor details of construction may be resorted'to within the scope of the invention without departing from the spirit or sacrificing any of the advantages thereof.

The operation of my adjustable surveying target is as follows: A suitable rod is marked oil into units conforming to the body port-ion length; the body portion 2 is then slipped on the rod and brought to the correct position as indicated by the surveyor sighting the target, and, clamped in this position, the distance the target is from the end of the rod may then be read off in units and fractions of units of the measure length used.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

In an adjustable surveying target of the class described, comprising a hollow metal body portion of a length of a standard unit of linear measure; a target integral with said body portion and positioned at one end thereof; a longitudinal open slot in said body portion; said body portion being provided with a scale containing numbered subdivisions of the unit on one side of the slot reading downward; and with a second scale on the opposite side of the slot, containing numbered subdivisions of the unit reading upward, whereby the units of measure marked on a suitable rod may be read in conjunction with said numbered subdivisions of the unit on the body portion, thus In testimony whereof I aflix my signature ifndicating ilslhe eza'ct distance, in unitsf and in the presence of tWo Witnesses. ractions t ereo the target is set rom either end of the rod; means for clamping 7 JOHN GILMORE MOMILLAN the hollow body portion in any desired WVitnesses: U position on any suitable rod, substantially as L. A. LARSON,

set forth. M. J. SELAYAV Copies of this patent may be obtained for five cents each, by addressing the Commissioner of late nts,

Washington, D. C. i 

